Re: APC Batteries.

["Andy Whitfield" <andywhitfield2002@xxxxxxxxxxx>]

Reply below.
--- In ukha_d@xxxxxxx, "domdevitto" <dom@...> wrote:
> Nope,
> I use a car charger to bring the batts to 100%, connected them to
the
> UPS and immediately after the first full 'to switchoff' use,
neither
> the UPS, nor a car charger could bring the batts back to life :-(

I would think the batteries had failed for other reasons.
I've had a car parked up where the battery was really flat - far
more than a UPS would let a battery go to.  Yet that charged up ok.
Sometimes using a regulated bench PSU is better than a car charger
or UPS.  Though you need to know what you're doing.

> Oh, one *vital* point, for anyone as crazy/stupid/intrepid as me,
UPSs
> are not designed to run on batts forever - the bypass circuits are
> often not thermally stable.  this means it'll get hot, possibly -
> depending of ambient temp - too hot and burn out.  I think running
a
> UPS700inet for 2 hours was pretty much breaking point - the circuit
> temp was very hot, but stable.  Normally you could expect 30
minutes
> of load going through the UPS circuitry, so was running 4 times
that,
> just.  But it was the batts that died, not the UPS circuitry.

The problem here is the 700 doesn't have a fan so the heat would
build up and up.  Bigger UPSs with fans should cope with longer
runtimes.

> Note: Acid-filled boxes, high currents, sparks, hydrogen and very
hot
> electronics are not a great mix.
>
> I would say that modding a UPS3000, or other UPS that is designed
for
> external 'daisy chained' batteries is a *much* better idea, as
> deep-cycling is going to be harder/longer, and the circuitry is
much
> more likely to:
> a) be thermally stable and
> b) use higher quality components, designed to handle higher loads
for
> longer - e.g. not die after 3 hours of providing current.

An APC Smart 3000 and Smart 700 use basically the same components.
The 3000 has more FETs to carry the load of course.

> I believe, from the last time I was at a datacentre (yesterday!),
that
> 'proper' UPS tend to use lead-acid (same as car batteries) purely
for
> price, but I guess the circuitry switches off well before they are
> deep cycled [the generator should be up after a minute or so].
This
> makes sense, as gel-cells are more than twice the price, and space
> isn't a problem for building-wide UPS.

I wouldn't think they use wet acid (car) batteries indoors.  They
can vent hydrogen gas (not good in a closed room).  And if knocked
over can spill acid.
UPS batteries aren't the Gel type, they are AGM.
Andy

> Dom 'don't do this as home' De Vitto
>
> --- In ukha_d@xxxxxxx, "Andy Whitfield"
> <andywhitfield2002@> wrote:
> >
> > The UPS would have switched off way before the batteries were
deeply
> > discharged.
> > I'm guessing you left them discharged for a while before trying
to
> > charge them?
> > Never leave lead acid batteries discharged for more than a day
or
> > two.
> > Andy
> > --- In ukha_d@xxxxxxx, "domdevitto" <dom@> wrote:
> > >
> > > <idiot alert!>
> > > I modded a 700 to use 2x 12v car batteries, in series, and
got
> > great
> > > run time (over 2 hours, on my rack), but the first really
deep
> > cycle
> > > killed both the batts.
> > >
> > > The APC 700s are pretty smart, and learn the charging
profile
of
> > the
> > > batts, but it'll still let them discharge fully - which in
my
case
> > was
> > > too much.
> > >
> > > Gel cells don't mind deep-cycle, so this should work
perfectly.
> > and
> > > you don't need any baking powder :-) [don't ask!]
> > >
> > > Dom
> > > --- In ukha_d@xxxxxxx, Wayne <Wayne@> wrote:
> > > >
> > > > Hi all,
> > > > I have a APC SmartUPS 700 with batteries that the APC
thinks
> > needs
> > > to be
> > > > replaced. I have managed to get hold of a set from an
APC
> > SmartUPS 750.
> > > >
> > > > Does anyone know if they are compatible at all?
> > > >
> > > > They physically fit the UPS and seem to charge and keep
the
> > power to a
> > > > pc when I pull the mains connection. The only thing
that
seems a
> > little
> > > > 'odd' is when I pull the power and go onto battery, the
ups
> > normally
> > > > beeps to let you know something not right - which it
now
doesn't
> > > seem to.
> > > >
> > > > One other difference - the newer battery set had a
connector
> > block that
> > > > was attached to the battery red/black spade connectors
-
when
> > they were
> > > > pulled from the 750 it has what looked like a 'quick
connector'
> > > block at
> > > > the back of the battery bay. My 700 just has two leads
that
> > connect to
> > > > the black/red battery terminals that disappear into the
ups..
> > > >
> > > > There isn't any markings on the newer set of batteries
that
> > suggest
> > > size
> > > > or rating otherwise I could compare.
> > > >
> > > > any ideas?
> > > >
> > > > Cheery
> > > > Wayne.
> > > >
> > >
> >
>